交联酸加砂压裂技术的研究和应用

Research and application of crosslinked acid-adding proppant fracturing technology

关键词:  碳酸盐岩  交联酸  酸携砂压裂  导流能力  酸压 

Key words:  carbonate  crosslinked acid  acid-adding proppant fracturing  conductivity  acid-fracturing

摘要:

塔里木碳酸盐岩储层非均质性强,裂缝和孔洞关系复杂,在裂缝和孔洞不发育的低品位储层进行酸压效果差。在分析酸压和压裂特点的基础上,开展了交联酸携砂压裂技术研究和现场试验。该技术是携砂液使用交联酸,形成带有酸液刻蚀和支撑剂支撑的复合人工裂缝,扩大储层和人工裂缝的接触面积。交联酸耐温流变性和携砂性能好,酸岩反应过程中能保持较高的黏度和携砂能力。在酸岩反应速度和导流实验研究的基础上,提出在携砂阶段使用不同浓度酸液的工艺方法,在缝端和缝口分别发挥酸液刻蚀和压裂支撑的优势,保持人工裂缝的高导流值。交联酸压裂技术在塔里木油田现场应用8井次,施工成功率100%,为塔里木油田碳酸盐岩储层高效开发提供了新的技术路径。

Abstract:

The carbonate reservoirs in Tarim Oilfield are generally characterized with strong heterogeneity, complex relation between natural fractures and pore space, and unacceptable acid-fracturing effect in the reservoir with poor fissures and pore. On the basis of analyzing the characteristics of acid-fracturing and sand fracturing, the research and field trials of acid-adding proppant fracturing is proposed. The slurry of acid-adding proppant fracturing is crosslinked acid, compound artificial fractures with acidizing etch and propping agent are formed, which enlarges the contact area between reservoir and fractures. Because of the good rheological property of heat-resistant and carrier performance, high viscosity and sand laden are kept during treatment. Based on the acid-rock reaction and conductivity experiments, different acid strength of crosslinking acid is used to transport proppant in different treating stages with the purpose of high fracture conductivity. Eight wells have been treated by this technique, with a construction success ratio of 100, as this technology integrates the advantages of acid fracturing and prop fracturing, a new approach to develop lean carbonate reservoir is promising in Tarim Oilfield.